close all
a=[-2 -2];
b=[0,3];
c=[4,-1];
d=[6,4];

ceuArrow(a,b,'r',2,'-',0)
axis square
axis([-3 7 -3 5])
ceuArrow(a,b,'r',2,'-',0)
ceuArrow(b,d,'r',2,'-',0)
ceuArrow(d,c,'r',2,'-',0)
ceuArrow(c,a,'r',2,'-',0)
grid on
xlabel('x_1')
ylabel('x_2')

text(a(1)-0.3,a(2)-0.2,'A')
text(b(1)-0.3,b(2)+0.2,'B')
text(c(1)+0.2,c(2)-0.1,'C')
text(d(1)+0.2,d(2)+0.1,'D')
